Endoscope

ABSTRACT

An endoscope has a first bending portion, a second bending portion, and a hand-held unit. The first bending portion is the distal portion of an elongated insertion member and has a plurality of joint pieces concatenated so that the joint pieces can rotate freely. The second bending portion is located at the proximal end of the first bending portion, and has a plurality of joint pieces concatenated so that the joint pieces can rotate freely. The hand-held unit is located at the proximal end of the insertion member, and has a control section that is used to bend the first bending portion and second bending portion. In the endoscope, the control section of the hand-held unit has an angling knob that is used to bend the first bending portion, and a second angling lever that is used to bend the second bending portion.

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2000-302470, filed on Oct. 2,2000 and No. 2001-232162 filed on Jul. 31, 2001 in Japan, the entirecontents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an endoscope, or more particularly, toan endoscope having two bending portions of a first bending portion anda second bending portion.

2. Description of the Related Art

Endoscopes have an elongated insertion member thereof inserted into thestomach, the intestine or any other organ of a living body or a tortuoushollow of a machine. The stomach, the intestine, and other organs arethree-dimensional and complexly tortuous. The insertion member of anendoscope must therefore be angled three-dimensionally finely.

For example, an endoscope described in Japanese Examined PatentApplication Publication No. 5-16857 has an elongated insertion membercomposed of a first bending portion that is a distal portion and asecond bending portion that is located at the proximal end of the firstbending portion. Each of the bending portions has a plurality of jointpieces concatenated so that the pieces can rotate relatively to oneanother. Moreover, a sole angling mechanism is included in a controlsection of a hand-held unit included in an endoscope. The anglingmechanism enables selective bending of the first and second bendingportions.

The endoscope described in the Japanese Examined Patent ApplicationPublication No. 5-16857 enables a user to selectively freely bend thefirst bending portion and second bending portion. However, since thesole angling mechanism is used to selectively bend the first and secondbending portions, there is a fear that the bending portion differentfrom the bending portion that must be bent may be manipulatedincorrectly.

Moreover, the endoscope described in the Japanese Examined PatentApplication Publication No. 5-16857 has a drawback that the two bendingportions cannot be manipulated simultaneously.

Furthermore, when one of the bending portions of the endoscope describedin the Japanese Examined Patent Application Publication No. 5-16857 isunused, the maneuverability of the endoscope is poorer than that of anordinary endoscope having one bending portion.

The peripheries of the bending portions are sheathed with a bendingrubber in order to keep the bending portions watertight. An amount offorce required to bend the bending portions depends on the hardness ofbuilt-in components or the hardness of the bending rubber.

In order to bend the bending portions so that the bending portions willassume sufficient bending angles, it is necessary to apply a largeramount of force to the second bending portion than to the first bendingportion. However, when a large amount of force is applied, a coil pipemay contract, the bending pieces may deform, or any other phenomenon mayoccur. While the use period of the endoscope gets longer, there arises afear that the bending portions may not be able to bend to assume desiredbending angles.

In order to overcome the poorness in bending smoothness, the ratio ofbuilt-in components to the inner diameter of the bending portion shouldbe reduced by increasing the inner diameter. However, if the innerdiameter of the bending portion is increased, the outer diameter thereofincreases. This results in the poor inserting smoothness of theinsertion member.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide anendoscope having two bending portions that can be bent independently ofeach other, and offering the same level of maneuverability as anendoscope having one bending portion.

Another object of the present invention is to provide an endoscope whosebending portions can be bent with improved ease and do not deteriorateas time goes by have difficulty in assuming desired angles than they arein an initial state.

According to the present invention, there is provided an endoscopehaving a first bending portion, a second bending portion, a firstcontrol member, and a second control member. The first bending portionis the distal portion of an elongated insertion member, and the secondbending portion is located proximally to the first bending portion. Thefirst control member is included in a hand-held unit proximal to theinsertion member, and used to bend the first bending portion. The secondcontrol member is included in the hand-held unit proximal to theinsertion member, and used to bend the second bending portion.

According to the present invention, there is provided an endoscopehaving a first bending portion, a second bending portion, a firstcontrol member, a second control member, and an elastic member. Thefirst bending portion is the distal portion of an elongated insertionmember and has a plurality of joint pieces concatenated so that thejoint pieces can rotate freely. The second bending portion is locatedproximally to the first bending portion and has a plurality of jointpieces concatenated so that the joint pieces can rotate freely. Thefirst control member is included in a hand-held unit proximal to theinsertion member and used to bend the first bending portion. The secondcontrol member is included in the hand-held unit proximal to theinsertion member and used to bend the second bending portion. Theelastic member is used to sheathe the peripheries of the first andsecond bending portions.

According to the present invention, there is provided an endoscopehaving a first bending portion, a second bending portion, a firstcontrol member, a second control member, an elastic member, a firstcontrol wire, a first coil pipe, a second control wire, and a second oilpipe. The first bending portion is the distal portion of an elongatedinsertion member and has a plurality of joint pieces concatenated sothat the joint pieces can rotate freely. The second bending portion islocated proximally to the first bending portion and has a plurality ofjoint pieces concatenated so that the joint pieces can rotate freely.The first control member is included in a hand-held unit proximal to theinsertion member and used to bend the first bending portion. The secondcontrol member is included in the hand-held unit proximal to theinsertion member and used to bend the second bending portion. Theelastic member is used to sheathe the peripheries of the first bendingportion and second bending portion. The first control wire is runthrough the insertion member and pulled or slackened in order to bendthe first bending portion. The first coil pipe is run through theinsertion member and has the first control wire passed through it. Thesecond control wire is run through the insertion member and pulled orslackened in order to bend the second bending portion. The second coilpipe is run through the insertion member and has the second control wirepassed through it.

Other features of the present invention and the advantages thereof willbe fully apparent from the description below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the overall configuration of an endoscope system includingan endoscope in accordance with an embodiment of the present invention;

FIG. 2 is a sectional view showing a bending portion of an insertionmember included in the endoscope shown in FIG. 1;

FIG. 3A and FIG. 3B are explanatory diagrams showing bending piecesincluded in a first bending portion and a second bending portionrespectively;

FIG. 3A is an explanatory diagram showing a bending piece included inthe first bending portion;

FIG. 3B is an explanatory diagram showing a bending piece included inthe second bending portion;

FIG. 4 is an explanatory diagram showing the structure of a coil pipe;

FIG. 5 shows the appearances of a hand-held unit of the endoscope andits surroundings;

FIG. 6 is an explanatory diagram showing the hand-held unit of theendoscope shown in FIG. 5 and held with a hand;

FIG. 7 shows the appearance of a hand-held unit of an endoscope that hasan angling knob, which is used to manipulate the second bending portion,included in a second control subsection, and the appearance of itssurroundings;

FIG. 8 shows the appearance of a hand-held unit of an endoscope having afirst control subsection and a second control subsection in which theaxes of rotation cross at a right angle, and the appearance of thesurroundings of the hand-held unit;

FIG. 9 shows the appearance of a hand-held unit of an endoscope that hastwo angling knobs included in a second control subsection, and theappearance of its surroundings;

FIG. 10A to FIG. 10C are plan views showing other examples of an anglingknob included in the second control subsection;

FIG. 11 shows the appearance of another example of the angling knobincluded in the second control subsection;

FIG. 12 is an explanatory diagram showing an insertion member having abending portion composed of a first bending portion and a second bendingportion by which bending angles are assumed when bent are set;

FIG. 13 is an explanatory diagram showing movements made by theinsertion member shown in FIG. 12;

FIG. 14 is an explanatory diagram showing other movements made by theinsertion member shown in FIG. 12;

FIG. 15A to FIG. 15C are explanatory diagrams showing the bendingportion shown in FIG. 12 and adapted to other endoscopes;

FIG. 15A is an explanatory diagram showing the insertion member of aconventional enlarged-view endoscope;

FIG. 15B is an explanatory diagram showing the insertion member of aconventional endoscope having two forceps passage channels;

FIG. 15 C is an explanatory diagram showing the insertion member of theenlarged-view endoscope shown in FIG. 15A or the endoscope having twoforceps passage channels as shown in FIG. 15B, wherein the insertionmember has the bending portion shown in FIG. 12;

FIG. 16A and FIG. 16B are explanatory diagrams showing an insertionmember that has a second bending portion thereof made shorter than afirst bending portion thereof;

FIG. 16A shows an explanatory diagram showing the insertion member whosesecond bending portion is shorter than the first bending portionthereof;

FIG. 16B is an explanatory diagram showing a case where the insertionmember shown in FIG. 16A is inserted into a tortuous lumen;

FIG. 17A to FIG. 17C are explanatory diagrams showing a case where anendoscope is used to observe the cardia of the stomach and itssurroundings;

FIG. 18A and FIG. 18B are explanatory diagrams showing an insertionmember that has a first bending portion thereof made shorter than asecond bending portion thereof;

FIG. 18A is an explanatory diagram showing the insertion member whosefirst bending portion is shorter than the second bending portionthereof;

FIG. 18B is an explanatory diagram showing a case where the insertionmember shown in FIG. 18A is inserted in a lumen that is hardly curved;

FIG. 19 is an explanatory diagram showing a case where an insertionmember characterized in that the number of the directions in which asecond bending portion thereof is bent is limited to a minimum necessarynumber of directions is inserted in a lumen in which only a specificobject can be observed;

FIG. 20A to FIG. 20C are explanatory diagrams showing angulation wiresthat are arranged at positions in the second bending portion that ensureeasy bending in oblique directions;

FIG. 20A is a sectional view showing angulation wire locks included inthe second bending portion in order to lock two second wires that arearranged at an Up position and a Right position;

FIG. 20B is a sectional view showing angulation wire locks included inthe second bending portion in order to lock two second wires that arearranged at Down and Left positions;

FIG. 20C is a sectional view showing angulation wire locks included inthe second bending portion in order to lock two second wires that arearranged at an intermediate position between Up and Right positions andan intermediate position between Down and Left positions;

FIG. 21 is an explanatory diagram showing the insertion member of aconventional endoscope whose bending portion is composed of a firstbending portion and a second bending portion;

FIG. 22 is a schematic explanatory diagram showing an insertion memberwhose bending portion includes a second bending portion that can bestraightened; and

FIG. 23 is a schematic explanatory diagram showing an insertion memberthat is a variant of the insertion member shown in FIG. 22.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the present invention will be described with referenceto the drawings below.

FIG. 1 to FIG. 9 are concerned with an embodiment of the presentinvention.

As shown in FIG. 1, an endoscope system 1 having the embodiment of thepresent invention consists mainly of an electronic endoscope(hereinafter simply an endoscope) 2, a light source apparatus 3, a videoprocessor 4, and a monitor 5. The electronic endoscope 2 has an imagepick-up means that is not shown. The light source apparatus 3 isconnected to the endoscope 2 so that it can be disconnected freely, andsupplies illumination light to the endoscope 2. The video processor 4 isconnected to the endoscope 2 so that it can be disconnected freely. Thevideo processor 4 controls the image pick-up means included in theendoscope 2 and processes a signal produced by the image pick-up meansto transmit a standard video signal. The monitor 5 displays anendoscopic image according to a signal processed by the video processor4.

A VTR deck, a video printer, a video disk drive, an image file recordingapparatus, or the like, not shown, can be connected to the videoprocessor 4.

The endoscope 2 has an elongated insertion member 11 that is insertedinto a region to be observed. A hand-held unit 12 is located at theproximal end of the insertion member 11. The hand-held unit 12 includesa control section 12 a that is used to bend first and second bendingportions that will be described later.

A universal cord 13 is extended from the lateral side of the hand-heldunit 12. A signal cable that is routed to the image pick-up means whichis not shown and a light guide over which illumination light ispropagated are contained in the universal cord 13.

A connector 14 is attached to the end of the universal cord 13. Theconnector 14 is coupled to the light source apparatus 3 and connected tothe video processor 4 such that it can be connected and disconnectedfreely.

A distal part 21 is located at the distal end of the insertion member11. A bending portion 22 capable of freely bending is located at theproximal end of the distal part 21. A flexible tube 23 is located at theproximal end of the bending portion 22. The flexible tube 23 is formedwith an elongated member that is soft and tubular.

An image pick-up unit in which a solid-state image pick-up device thatis not shown, such as, a CCD and a circuit board for driving thesolid-state image pick-up device are incorporated is included as theimage pick-up means in the distal part 21. The distal end of the lightguide is extended to the distal part 21, whereby illumination lightpropagated from the light source apparatus 3 is radiated to a region tobe observed in a body cavity. The region to be observed is thusilluminated.

The bending portion 22 is composed of two bending portions, that is, afirst bending portion 24 that is the distal half of the bending portion22 and a second bending portion 25 that succeeds the first bendingportion 24.

To begin with, the structure of the bending portion 22 will be describedin conjunction with FIG. 2 to FIG. 5.

As shown in FIG. 2, the first bending portion 24 and second bendingportion 25 each has a plurality of bending pieces 31 concatenated sothat the bending pieces can rotate freely. The plurality of bendingpieces 31 are sheathed with a bending braid 32 made by cylindricallyweaving thin wires. The bending braid 32 is sheathed with a bendingrubber 33 and thus kept watertight.

The bending braid 32 and bending rubber 33 may be used to sheathe thebending portion 22 composed of the first bending portion 24 and secondbending portion 25 over the whole length of the bending portion 22.Otherwise, the first bending portion 24 and second bending portion 25may be sheathed with the bending braid 32 and bending rubber 33independently of each other.

First wires 34 used to pull and bend the first bending portion 24 areextended from the distal end of the first bending portion 24.

Second wires 35 used to pull and bend the second bending portion 25 areextended from the distal end of the second bending portion 25.

The first wires 34 are passed through first coil pipes 36 fixed to thedistal end of the second bending portion 25, and thus routed to a firstcontrol subsection 42, which will be described later, by way of theinsertion member 11.

Moreover, the second wires 35 are passed through second coil pipes 37fixed to the distal end of the flexible tube 23, and thus routed to asecond control subsection 44, which will be described later, by way ofthe insertion member 11.

Furthermore, the thickness of the portion of the bending rubber 33 withwhich the second bending portion 25 is sheathed is smaller than thethickness of the portion thereof with which the first bending portion 24is sheathed. Consequently, the second bending portion of the bendingportion 22 is more easily bent. Even if a larger number of built-incomponents must be put in the second bending portion 25, the outerdiameter of the second bending portion 25 need not be increased. Theease of bending characterizing the bending portion 22 will therefore notdeteriorate.

Generally, when the bending portion 22 is bent, a larger load is oftenimposed on the second bending portion 25 than on the first bendingportion 24. This is because the second bending portion 25 accommodates alarger number of built-in components.

For this reason, the bending pieces 31 constituting the second bendingportion 25 of the bending portion 22 are, as shown in FIG. 3A and FIG.3B, made thicker than those constituting the first bending portion 24.

In other words, bending pieces 31 b used to construct the second bendingportion 25 of the bending portion 22 as shown in FIG. 3B are madethicker than bending pieces 31 a used to construct the first bendingportion 24 as shown in FIG. 3A.

Consequently, even when a larger magnitude of force is applied to thesecond bending portion 25 than to the first bending portion 24, thebending pieces 31 constituting the second bending portion 25 hardlydeform. Thus, a bending angle the second bending portion 25 assumes whenbent is set will not get smaller than a bending angle it assumes in aninitial state.

Moreover, coil pipes used as the first coil pipes 36 and second coilpipes 37 are made by, as shown in FIG. 4, finely winding a thin wire sothat adjoining portions of the wire will be closely in contact with eachother. Owing to this structure, the whole length of the coil pipe may beshortened with application of a load of compression. For this reason,the diameter of a wire used to make the second coil pipes 37 fixed tothe proximal end of the second bending portion 25 that must incur alarger load is made larger than the diameter of a wire used to make thefirst coil pipes 36. Consequently, the second coil pipes 37 are hardlycompressed because they are made using a thicker wire than the firstcoil pipes 36 are. Therefore, even if a larger magnitude of force isapplied to the second bending portion 25 than to the first bendingportion 24, the coil pipes will not contract. Thus, a bending angle thesecond bending portion assumes when bent is set will not get smallerthan the one it assumes in an initial state

According to the present embodiment, the control section 12 a of thehand-held unit 12 consists of the first control subsection 42 and secondcontrol subsection 44. The first control subsection 42 is used to bendthe first bending portion 24. The second control subsection 44 is usedto bend the second bending portion 25. Owing to the structure, the firstbending portion 24 and second bending portion 25 can be bentindependently of each other.

The first control subsection 42 includes, as shown in FIG. 5, anglingknobs 42 a and 42 a′ and first locking levers 42 b and 42 b′. Theangling knobs 42 a and 42 a′ are used to bend the first bending portion24. The first locking levers 42 b and 42 b′ are used to lock the anglingknobs 42 a and 42 a′ at desired angular positions

The second control subsection 44 includes, as shown in FIG. 5, a secondangling lever 44 a used to bend the second bending portion 25 and asecond locking lever 44 b used to lock the second angling lever 44 a ata desired angular position.

The control section 12 a has an electric switch subsection 43 thatincludes remote switches 43 a used to instruct the video processor 4 tofreeze or unfreeze a view image.

The angling knob 42 a is a knob used to bend the first bending portion24 in Up and Down directions. The angling knob 42 a′ is a knob used tobend the first bending portion 24 in Right and Left directions.

The first locking lever 42 b is a lever used to lock the angling knob 42a at a desired angular position. The first locking lever 42 b′ is a knobused to lock the angling knob 42 a′ at a desired angular position.

Furthermore, the first control subsection 42 includes anaeration/perfusion button 42 c used to instruct aeration or perfusionand a suction button 42 d used to instruct suction.

The endoscope 2 having the foregoing components is used to performendoscopic examination.

In general, an operator holds, as shown in FIG. 6, the hand-held unit 12with his/her left hand so as to angle the endoscope.

In this case, for example, the hand-held unit 12 is borne with the rootof the thumb of the left hand and the ring finger and little finger ofthe left hand. The angling knob 42 a and second angling lever 44 a aremanipulated using the thumb. The index finger and middle finger are alsoused to manipulate the angling knob 42 a and second angling lever 44 awhen these fingers are not manipulating the remote switches 43 a and thebuttons including the aeration/perfusion button 42 c and suction button42 d.

When an operator wants to bend the first bending portion 24, theoperator bears the hand-held unit 12 with the root of the thumb of theleft hand and the ring finger and little finger thereof. The operatorthen manipulates the angling knob 42 a using the thumb, index finger, ormiddle finger thereof. At this time, the angling knob 42 a lies withinreach of the thumb, index finger, or middle finger.

Moreover, when an operator wants to bend the second bending portion 25,the operator manipulates the second angling lever 44 a with his/herright hand that does not hold the hand-held unit 12.

The thumb, index finger, or middle finger may be stretched to a positionthat is usually beyond reach of it in order to manipulate the secondangling lever 44 a.

When the remote switches 43 a are used or endoscopic treatment iscarried out, the first locking levers 42 b and 42 b′ and the secondlocking lever 44 b may be used to lock the angling knobs 42 a and 42 a′and the second angling lever 44 a at desired angular positions. In thiscase, the thumb can be separated from the hand-held unit, and theendoscope can be manipulated with the insertion member retained in adesired bent state.

Moreover, the second control subsection 44 is separated from the firstcontrol subsection 42 with the electric switch subsection 43 betweenthem. When the angling knob 42 a is manipulated, the fingers with whichthe angling knob is manipulated will not come in contact with the secondangling lever 44 a.

The second angling lever 44 a may be, as shown in the plan view of FIG.10A, jutted out in a direction opposite to the direction of the anglingknobs 42.

The foregoing structure may be modified in consideration of ease withwhich the second angling lever 44 a can be manipulated with, forexample, the right hand, so that the second angling lever 44 a will jutout towards the angling knobs 42 as shown in FIG. 10B and FIG. 10C.

Referring to FIG. 5 and FIG. 6, the second angling lever 44 a that is alever used to bend the second bending portion 25 is included in thesecond control subsection 44. However, the present invention is notlimited to the second angling lever 44 a. As shown in FIG. 7, when thesecond bending portion can be bend in freely selected directions, anangling knob 44 c that resembles the angling knob 42 a may besubstituted for the second angling lever 44 a.

The axes of rotation in the first control subsection 42 and secondcontrol subsection 44 may extend parallel to each other as shown in FIG.5. Alternatively, the axes of rotation may meet at an angle as shown inFIG. 8. Referring to FIG. 8, the axes of rotation in the first controlsubsection 42 and second control subsection 44 cross at right angles.

Moreover, when the second bending portion 25 is designed to be able tobend in four directions, the second control subsection 44 includes twoangling knobs 44 c as shown in FIG. 9. The second bending portion 25 canthus be bent in four directions.

Consequently, in the endoscope 2 in accordance with the presentembodiment, the first and second bending portions 24 and 25 can be bentindependently of each other. The two bending portions can be handled inthe same manner as an ordinary bending portion is. The endoscope 2 ofthe present embodiment offers improved ease of bending.

The endoscope 2 of the present embodiment has the second controlsubsection 44 separated from the first control subsection 42.Consequently, when the first control subsection 42 alone is used, thesecond control subsection will not annoy an operator. The endoscopeoffers ease of bending of the same level as a normally employedendoscope having one bending portion does.

Furthermore, the endoscope 2 of the present embodiment has the secondcontrol subsection 44 and first control subsection 42 separated fromeach other with the electric switch subsection 43 between them.Consequently, the maneuverability offered by the endoscope will not bepoorer than the maneuverability offered by an ordinary endoscope. Inaddition, when the first control subsection 42 and electric switchsubsection 43 are used, the second control subsection 44 will not bemanipulated incorrectly.

In the endoscope 2 of the present embodiment, the axes of rotation inthe first control subsection 42 and second control subsection 44 meet atan angle. Consequently, when the first control subsection 42 is heldwith one hand and the second control subsection 44 is manipulated withthe other hand, the second control subsection 44 can be manipulatedeasily.

The endoscope 2 in accordance with the present embodiment is anelectronic endoscope having the image pick-up unit incorporated in thedistal part 21 of the insertion member 11. Alternatively, the presentinvention may be implemented in an electronic endoscope in which animage guide that is not shown is run through the insertion member 11 andan object image propagated along the image pick-up guide is picked up byan image pick-up unit incorporated in the control section 12 a.Moreover, the present invention may be implemented in a so-calledoptical endoscope in which an object image propagated along the imageguide is viewed through an eyepiece unit mounted on the control section12 a. In any case, the endoscope has the bending portion 22 composed ofthe first bending portion 24 and second bending portion 25.

The present invention is not limited to the aforesaid embodiment, butcan be modified in various aspects with the gist of the presentinvention left unchanged.

For example, as shown in FIG. 11, the second angling lever 44 a may belocated at a position at which a forceps lift lever is usually locatedin an ordinary endoscope.

As far as observation of an intracavitary region is concerned, observinga region to be observed from the front side thereof is very helpful in aviewpoint of producing a clear image devoid of deformation.

When an endoscope has the same structure as the aforesaid one, that is,the elongated insertion member 11 has the bending portion 22 composed ofthe first bending portion 24 and second bending portion 25, the firstbending portion 24 and second bending portion 25 are bent independentlyof each other. Thus, the distal part 21 of the insertion member can befaced a region to be observed.

For example, the insertion member 11 may be in close contact with theintracavitary wall as shown in FIG. 21. In this case, the second bendingportion 25 is bent upward by an angle θ with respect to the longitudinalaxis of the insertion member 11. At the same time, the first bendingportion 24 is bent downwards by an angle θ+90° with respect to thelongitudinal axis of the insertion member 11. Consequently, the distalpart 21 of the insertion member 11 is angled to face a region to beobserved that is located on an intracavitary wall.

FIG. 21 is an explanatory diagram showing the insertion member of aconventional endoscope having a bending portion composed of a firstbending portion and a second bending portion.

However, assume that the insertion member 11 is in close contact with anintracavitary wall, and that the distal part 21 of the insertion memberis faced the intracavitary wall. In this case, the distal part 21 islocated near an extension of the longitudinal axis of the flexible tube23 (which is in close contact with the intracavitary wall) of theinsertion member 11. Consequently, the distal part 21 cannot have apredetermined distance from the region to be observed.

If the distal part 21 cannot be separated from a region to be observedby a predetermined distance, it is hard to observe the region to beobserved during endoscopic examination. Although the predetermineddistance cannot be preserved, if an attempt is made to performendoscopic treatment, a therapeutic instrument or the like may not beable to be projected from the distal part 21 towards an intracavitarywall. Consequently, the endoscopic treatment fails.

In order to solve the above problem, it is conceivable to increase thedimension of the second bending portion 25. The second bending portion25 is bent appropriately in order to raise the first bending portion 24relative to the intracavitary wall, whereby the predetermined distancemay be preserved. However, this structure has a drawback that theoverall length of the bending portion 22 is too large.

The bending portion 22 has, as described in conjunction with FIG. 2, theplurality of bending pieces 25 sheathed with the braid 32 and bendingrubber 33. The surface of the bending portion 22 is therefore finelyirregular and hardly smooth. The bending portion 22 must therefore havea minimum necessary length.

There is therefore a long-persistent demand for an endoscope that offersimproved ease of observation and treatment when the distal part 21 isfaced an intracavitary wall with both the first bending portion 24 andsecond bending portion 25 bent.

Referring to FIG. 12 to FIG. 20C, an example of the structure of anendoscope including two bending portions will be described below.

FIG. 12 to FIG. 20C show the example of the structure of an endoscopeincluding two bending portions.

As shown in FIG. 12, the first bending portion 24 and second bendingportion 25 are bent, and the distal part 21 of the insertion member isthus angled in a direction perpendicular to the longitudinal axis of theinsertion member 11, that is, faced an intracavitary wall. In thisstate, bending angles the first bending portion 24 and second bendingportion 25 that constitute the bending portion 22 assume when bent isset are determined so that the distal part 21 will always lie above anextension of the longitudinal axis of the insertion member 11 (so thatthe distal part 21 can be distanced from a region to be observed).

Referring to FIG. 12, the bending angle the second bending portion 25assumes when bent, θ, is set substantially to 90° and the bending anglethe first bending portion 24 assumes when bent, (θ+90°), is setsubstantially to 180°.

The thus-structured bending portion 22 is adapted to a conventionalenlarged-view endoscope 2A that has, as shown in FIG. 15A, an imagepick-up unit (not shown), of which focus can be changed from one toanother, incorporated in the distal part 21. Otherwise, the bendingportion 22 is adapted to a conventional endoscope 2B having, as shown inFIG. 15B, two forceps passage channels 51.

As shown in FIG. 15A, the conventional enlarged-view endoscope 2A hasthe insertion member 11 that includes one bending portion. Therefore,the distal part 21 is located on or near an extension of thelongitudinal axis of the flexible tube 23 (that is in close contact withan intracavitary wall) along the intracavitary wall. It is thereforehard to observe a lesion located tangentially to the intracavitary wall.

Referring to FIG. 15B, a predetermined distance cannot be preservedbetween the distal part 21 of the insertion member of the endoscope 2Bhaving two forceps passage channels 51 and a region to be observed. Atherapeutic instrument 52 or the like cannot be projected from thedistal part 21. It is therefore hard to perform endoscopic treatment.

Now, when the bending portion 22 is structured as shown in FIG. 12, thedistance between the distal part 21 and a region to be observed can beadjusted as shown in FIG. 15 c. Moreover, two therapeutic instrumentscan be used for endoscopic treatment.

As shown in FIG. 13, when a lesion is observed, the first bendingportion 24 and second bending portion 25 are bent, and the secondlocking lever 44 b is manipulated in order to lock the second anglinglever 44 a at a desired angular position. Consequently, the secondbending portion 25 can be retained in a desired bent state. The firstbending portion 24 is bent vertically and laterally with the secondangling lever 44 a locked. Eventually, the distal part of the endoscopecan be angled in the directions of arrows with the lesion and distalpart distanced from each other.

In short, observation can be continued with the relative positions ofthe lesion and the distal part varied.

Furthermore, as shown in FIG. 14, the first locking levers 42 b and 42b′ are manipulated to lock the bending knobs 42 at desired angularpositions. Consequently, the first bending portion 24 is retained in adesired bent state. In this state, the second bending portion 25 is bendin two directions. Thus, the distal part of the endoscope can be angledin the directions of arrows while faced the lesion.

In short, the distance between the lesion and the distal part of theendoscope can be adjusted with the distal part angled to the lesion.

As shown in FIG. 13 and FIG. 14, the first bending portion 24 and secondbending portion 25 can be retained in respective bent states. This leadsto improved ease of manipulation offered for endoscopic observation.

Furthermore, the bending portion 22 may be designed such that the secondbending portion 25 will be shorter than the first bending portion 24 asshown in FIG. 16A. For example, when the endoscope is used to observe atortuous lumen such as the lumen of the large intestine, even if thesecond bending portion 25 is bent, the second bending portion 25 willnot interfere with the intestinal wall but the bending portion 22 can beentirely moved.

In contrast with FIG. 16A, FIG. 18A shows the bending portion having thesecond bending portion 25 made longer than the first bending portion 24.As shown in FIG. 18B, when the bending portion is inserted in a lumenthat is almost not at all curved, for example, the lumen of the stomach,ease of insertion or treatment can be improved. Namely, a therapeuticinstrument can be inserted easily during endoscopic treatment, or thedistal part 21 of the insertion member can be angled easily finely.

As shown in FIG. 17A, when an endoscope has only one bending portion,the bending portion can be bent in order to position the distal partclosely to the cardia of the stomach. However, the cardia and itssurroundings are observed obliquely. It is therefore hard to view thecardia and its surroundings from the front sides thereof.

As shown in FIG. 17B, when the second bending portion 25 is somewhatlong, since the second bending portion 25 must be fully jutted out ofthe esophagus, the first bending portion 24 recedes from the cardia ofthe stomach. Therefore, even if an attempt is made to bend the firstbending portion in order to observe the cardia and its surroundings, thedistance between the distal part of the endoscope and the cardia is toolarge to achieve observation successfully.

Now, in an endoscope shown in FIG. 17C, the dimension of the secondbending portion 25 in a direction of insertion is smaller than thedimension of the first bending portion 24 therein. When the dimensionsof the first and second bending portions 24 and 25 in the direction ofinsertion are thus set, if the first and second bending portions 24 and25 are bent in order to observe the cardia of the stomach and itssurroundings, the distal part of the endoscope can be positioned closelyto the cardia. This results in successful observation.

As shown in FIG. 19, an endoscope may be used exclusively to observe,for example, the duodenum. In this case, the second bending portion 25is made bendable in only one direction (an Up or Down direction). Likethis, the number of the bendable directions of the second bendingportion 25 is limited to a minimum necessary number of directions. Thisleads to a simplified angling mechanism.

FIG. 19 shows a case where the distal part 21 of the insertion member ismade to approach the duodenal papilla.

When the duodenal papilla or any other region of the duodenum isincised, the distal end of an endoscope should be made to approachobliquely for more successful treatment.

In this case, the second wires 35 to be pulled in order to bend thesecond bending portion 25 may be arranged as shown in FIG. 20A to FIG.20C.

As shown in FIG. 20A and FIG. 20B, the second wires 35 lying through thesecond bending portion 25 may be arranged at Up and Right positions orDown and Left positions so that the second bending portion 25 can beeasily bent obliquely.

As shown in FIG. 20C, the second wires 35 lying through the secondbending portion 25 may be arranged at an intermediate position betweenthe Up and Right positions and an intermediate position between the Downand Left positions.

As far as the aforesaid endoscope whose elongated insertion member 11has the bending portion 22 is concerned, the second bending portion 25of the bending portion 22 is first bent. Namely, the one of the secondwires 35 described in conjunction with FIG. 2, which is located at theUp position, is pulled in order to bend the second bending portion 25 inthe Up direction. If the second bending portion 25 is straightenedthereafter, since restoring force exerted by the bending rubber 33 withwhich the second bending portion 25 is sheathed is weak, the one of thesecond wires 35 which is located at the Down position must be pulled.Therefore, an angling mechanism is very complex.

There is therefore a demand for an endoscope having a simple structureand having the second bending portion 25 capable of being straightened.

Referring to FIG. 22 and FIG. 23, an example of the structure of anendoscope whose second bending portion can be straightened will bedescribed below.

As shown in FIG. 22, the first bending portion 24 of the bending portion22 has a plurality of bending pieces 31 concatenated so that the bendingpieces can rotate freely. The concatenated bending pieces 31 aresheathed with the bending braid 32 made by cylindrically weaving thinwires, and then covered with the bending rubber 33.

The second bending portion 25 has, similarly to the first bendingportion 24, the plurality of bending pieces 31 concatenated so that thebending pieces can rotate freely. The bending pieces 31 are sheathedwith the bending braid 32. The bending braid 32 is coated with aresilient resin 61 such as polyester which is the same resin as thatadopted for the flexible tube 23.

Consequently, the second bending portion 25 has the bending braid 32coated with the resilient resin 61 that is the same resin as thatadopted for the flexible tube 23. Therefore, the second bending portion25 that has been bent can be straightened by merely slackening one ofthe second wires 35. Namely, the second wire 35 to be slackened is asecond wire that has been pulled in order to bend the second bendingportion 25 in a direction that runs externally parallel to the secondwire.

Moreover, the second wires 35 used to bend the second bending portion 25may lie, as shown in FIG. 23, alone at one position, so that the secondbending portion 25 can be bent in only one direction.

As described in conjunction with FIG. 2, the second wires 35 are passedthrough the second coil pipes 37 inside the flexible tube 23 up to theproximal end of the second bending portion 25.

The second bending portion 25 has the same structure as, for example,the flexible tube 23 (for example, as shown in FIG. 22, molded using thesame resin 61 as that adopted for the flexible tube 23). Thus, thesecond bending portion 25 is easily straightened.

Consequently, when the second wires 35 are not tensioned, the secondbending portion 25 is automatically straightened. Only one of the secondwires 35 can therefore be used to bend or straighten the second bendingportion 25. Herein, a position of the second wire defines one directionin which the second bending portion 25 can be bent.

The present invention is not limited to the aforesaid embodiment but canbe modified in various aspects with the gist thereof left unchanged.

As described so far, according to the present invention, there isprovided an endoscope having two bending portions that can be bentindependently of each other, and offering ease of bending of the samelevel as that an endoscope having one bending portion offers.

According to the present invention, it is apparent that a wide range ofdifferent embodiments can be formed based on the invention without adeparture from the spirit and scope of the present invention. Thepresent invention is limited to the appended claims but not restrictedto any specific embodiment.

1. An endoscope comprising: a first bending portion that is the distalportion of an elongated insertion member; a second bending portionlocated at the proximal end of said first bending portion; a firstcontrol portion included in a hand-held unit proximal to said insertionmember, and used to bend said first bending portion; and a secondcontrol portion included in the hand-held unit proximal to saidinsertion member, and used to bend said second bending portion; whereinsaid first control portion is located nearer the part which is held withthe operator's hand than said second control portion.
 2. The endoscopeaccording to claim 1, wherein the axis of rotation of said first controlportion and the axis of rotation of said second control portion areextended in different directions.
 3. The endoscope according to claim 2,wherein the axis of rotation of said first control portion and the axisof rotation of said second control portion are extended substantiallyparallel to each other.
 4. The endoscope according to claim 2, whereinthe axis of rotation of said first control portion and the axis ofrotation of said second control portion are extended substantiallyperpendicularly to each other.
 5. The endoscope according to claim 1,wherein: said first control portion is arranged so that when saidhand-held unit is held, said first control portion will lie within reachof a finger of the hand with which said hand-held unit is held; and saidsecond control portion is arranged so that when said hand-held unit isheld, said second control portion will lie beyond reach of a finger ofthe hand with which said hand-held unit is held.
 6. The endoscopeaccording to claim 1, wherein an electric switch subsection used to givepredetermined instructions is interposed between said first controlportion and said second control portion.
 7. The endoscope according toclaim 6, wherein said electric switch subsection separates said firstcontrol portion and said second control portion from each other.
 8. Theendoscope according to claim 1, wherein said first control portion islocated in the distal part of a control section, and said second controlportion is located in the proximal part thereof.
 9. The endoscopeaccording to claim 8, wherein a manipulated portion of said firstcontrol portion and a manipulated portion of said second control portionare faced in the same direction.
 10. The endoscope according to claim 1,wherein: said first control portion is arranged so that when saidhand-held unit is held with the left hand, said first control portionwill lie within reach of a finger of the left hand with which saidhand-held unit is held; and said second control portion is arranged sothat when said hand-held unit is held with the left hand, said secondcontrol portion will lie beyond reach of a finger of the left hand withwhich said hand-held unit is held, and can be manipulated with a fingerof the right hand.
 11. The endoscope according to claim 10, wherein saidhand-held unit is borne with the root of the thumb of the left hand andthe ring finger and little finger thereof, and said first controlportion is manipulated with the thumb, index finger, or middle finger ofthe left hand.
 12. The endoscope according to claim 11, wherein whensaid first bending portion is bent, said first control portion ismanipulated using the thumb, index finger, or middle finger of the lefthand with said hand-held unit borne using the root of the thumb of theleft hand and the ring finger and little finger thereof, because saidfirst control portion is located at a position that is normally withinreach of the thumb, index finger, or middle finger of the left hand. 13.The endoscope according to claim 11, wherein when said second bendingportion is bent, said second control portion is manipulated with theright hand unused to hold said hand-held unit.
 14. The endoscopeaccording to claim 11, wherein when said second bending portion is bent,said second control portion is manipulated by stretching the thumb,index finger, or middle finger of the left hand with said hand-held unitborne using the root of the thumb of the left hand and the ring fingerand little finger thereof, although said second control portion islocated at a position that is normally beyond reach of the thumb, indexfinger, or middle finger of the left hand.
 15. The endoscope accordingto claim 1, wherein said first control portion includes a firstRight/Left control member that is used to bend said first bendingportion in a Right or Left direction, and a first Up/Down control memberthat is used to bend said first bending portion in an Up or Downdirection.
 16. The endoscope according to claim 1, wherein said secondcontrol portion includes a second Up/Down control member that is used tobend said second bending portion in an Up or Down direction.
 17. Theendoscope according to claim 16, wherein the second control portionfurther includes a second Right/Left control member that is used to bendthe second bending portion in a Right or Left direction.
 18. Theendoscope according to claim 1, wherein the second control portion iscomposed of a knob.
 19. The endoscope according to claim 1, wherein thesecond control portion is composed of a lever.
 20. The endoscopeaccording to claim 1, wherein the second control portion bends thesecond bending portion obliquely.
 21. The endoscope according to claim1, wherein the axis of rotation of the first control portion and theaxis of rotation of the second control portion are extended in the samedirection.
 22. The endoscope according to claim 1, wherein the firstcontrol portion and the second control portion are located in differentpositions.
 23. The endoscope according to claim 22, wherein the axis ofrotation of the first control portion and the axis of rotation of thesecond control portion meet at an angle.
 24. The endoscope according toclaim 22, wherein the second control portion is located in the proximalpart of the hand-held unit and the first control portion is locatednearer the insertion member than the second control portion in thehand-held unit.
 25. The endoscope according to claim 24, wherein thefirst control portion is arranged so that when the hand-held unit isheld, the first control portion will lie within reach of a finger of thehand with which the hand-held unit is held; and the second controlportion is arranged so that when the hand-held unit is held, the secondcontrol portion will lie beyond reach of a finger of the hand with whichthe hand-held unit is held.
 26. The endoscope of claim 1, wherein abending angle said first bending portion assumes when bent is set and abending angle said second bending portion assumes when bent is set aredetermined so that when said second bending portion is bent by an angleθ and said first bending portion is bent θ+90° or more in a directionopposite to the direction in which said second bending portion is bent,and when the distal portion of said insertion member is angled in adirection substantially perpendicular to the longitudinal axis of saidinsertion member, the distal portion of said insertion member will bedistanced from a tangent to the longitudinal axis of said insertionmember.
 27. An endoscope comprising: a first bending portion that is thedistal portion of an elongated insertion member and has a plurality ofjoint pieces concatenated so that the joint pieces can rotate freely; asecond bending portion located at the proximal end of said first bendingportion and has a plurality of joint pieces concatenated so that thejoint pieces can rotate freely; a first control portion included in ahand-held unit proximal to said insertion member, and used to bend saidfirst bending portion; a second control portion included in thehand-held unit proximal to said insertion member, and used to bend saidsecond bending portion; and an elastic member with which the peripheriesof said first bending portion and said second bending portion aresheathed; said first control portion is located nearer the part which isheld with the operator's hand than said second control portion.
 28. Theendoscope according to claim 27, wherein said first control portion islocated nearer the part which is held with the operator's hand than saidsecond control portion.
 29. The endoscope according to claim 28, whereinthe thickness of the portion of said elastic member with which theperiphery of said first bending portion is sheathed is different fromthe thickness of the portion thereof with which the periphery of saidsecond bending portion is sheathed.
 30. The endoscope according to claim29, wherein the portion of said elastic member with which the peripheryof said first bending portion is sheathed is thicker than the portionthereof with which the periphery of said second bending portion issheathed.
 31. The endoscope of claim 27, wherein a bending angle saidfirst bending portion assumes when bent is set and a bending angle saidsecond bending portion assumes when bent is set are determined so thatwhen said second bending portion is bent by an angle θ and said firstbending portion is bent θ+90° or more in a direction opposite to thedirection in which said second bending portion is bent, and when thedistal portion of said insertion member is angled in a directionsubstantially perpendicular to the longitudinal axis of said insertionmember, the distal portion of said insertion member will be distancedfrom a tangent to the longitudinal axis of said insertion member.
 32. Anendoscope comprising: a first bending portion that is the distal portionof an elongated insertion member and has a plurality of joint piecesconcatenated so that the joint pieces can rotate freely; a secondbending portion located at the proximal end of said first bendingportion and has a plurality of joint pieces concatenated so that thejoint pieces can rotate freely; a first control portion included in ahand-held unit proximal to said insertion member, and used to bend saidfirst bending portion; a second control portion included in thehand-held unit proximal to said insertion member, and used to bend saidsecond bending portion; and an elastic member with which the peripheriesof said first bending portion and said second bending portion aresheathed; wherein the thickness of said joint pieces constituting saidsecond bending portion is different from the thickness of said jointpieces constituting said first bending portion.
 33. The endoscopeaccording to claim 32, wherein said joint pieces constituting saidsecond bending portion are thicker than said joint pieces constitutingsaid first bending portion.
 34. An endoscope comprising: a first bendingportion that is the distal portion of an elongated insertion member andhas a plurality of joint pieces concatenated so that the joint piecescan rotate freely; a second bending portion located at the proximal endof said first bending portion and has a plurality of joint piecesconcatenated so that the joint pieces can rotate freely; a first controlportion included in a hand-held unit proximal to said insertion member,and used to bend said first bending portion; a second control portionincluded in the hand-held unit proximal to said insertion member, andused to bend said second bending portion; an elastic member with whichthe peripheries of said first bending portion and said second bendingportion are sheathed; a first control wire run through said insertionmember and pulled or slackened in order to bend said first bendingportion; a first coil pipe lying through said insertion member andhaving said first control wire passed through it; a second control wirerun through said insertion member and pulled or slackened in order tobend said second bending portion; and a second coil pipe lying throughsaid insertion member and having said second control wire passed throughit; wherein said first control portion is located nearer the part whichis held with the operator's hand than said second control portion. 35.The endoscope according to claim 34, wherein said first control portionis located nearer the part which is held with the operator's hand thansaid second control portion.
 36. The endoscope of claim 34, wherein abending angle said first bending portion assumes when bent is set and abending angle said second bending portion assumes when bent is set aredetermined so that when said second bending portion is bent by an angleθ and said first bending portion is bent θ+90° or more in a directionopposite to the direction in which said second bending portion is bent,and when the distal portion of said insertion member is angled in adirection substantially perpendicular to the longitudinal axis of saidinsertion member, the distal portion of said insertion member will bedistanced from a tangent to the longitudinal axis of said insertionmember.
 37. An endoscope comprising: a first bending portion that is thedistal portion of an elongated insertion member and has a plurality ofjoint pieces concatenated so that the joint pieces can rotate freely; asecond bending portion located at the proximal end of said bendingportion and has a plurality of joint pieces concatenated so that thejoint pieces can rotate freely; a first control portion included in ahand-held unit proximal to said insertion member, and used to bend saidfirst bending portion; a second control portion included in thehand-held unit proximal to said insertion member, and used to bend saidsecond bending portion; an elastic member with which the peripheries ofsaid first bending portion and said second bending portion are sheathed;a first control wire run through said insertion member and pulled orslackened in order to bend said first bending portion; a first coil pipelying through said insertion member and having said first control wirepassed through it; a second control wire run through said insertionmember and pulled or slackened in order to bend said second bendingportion; and a second coil pipe lying through said insertion member andhaving said second control wire passing there through; wherein thediameter of a wire wound to form said second coil pipe is different fromthe diameter of a wire wound to form said first coil pipe.
 38. Theendoscope according to claim 37, wherein the diameter of a wire wound toform said second coil pipe is larger than the diameter of a wire woundto form said first coil pipe.
 39. An endoscope comprising: a firstbending portion that is the distal portion of an elongated insertionmember and has a plurality of joint pieces concatenated so that thejoint pieces can rotate freely; a second bending portion located at theproximal end of said first bending portion and has a plurality of jointpieces concatenated so that the joint pieces can rotate freely; a firstcontrol portion included in a hand-held unit proximal to said insertionmember, and used to bend said first bending portion; a second controlportion included in the hand-held unit proximal to said insertionmember, and used to bend said second bending portion; and an elasticmember with which the peripheries of said first bending portion and saidsecond bending portion are sheathed; wherein the thickness of theportion of said elastic member with which the periphery of said firstbending portion is sheathed is different from the thickness of theportion thereof with which the periphery of said second bending portionis sheathed, the portion of said elastic member with which the peripheryof said first bending portion is sheathed being thicker than the portionthereof with which the periphery of said second bending portion issheathed, and said first control portion is located nearer the partwhich is held with the operator's hand than said second control portion.40. The endoscope of claim 39, wherein a bending angle said firstbending portion assumes when bent is set and a bending angle said secondbending portion assumes when bent is set are determined so that whensaid second bending portion is bent by an angle θ and said first bendingportion is bent θ+90° or more in a direction opposite to the directionin which said second bending portion is bent, and when the distalportion of said insertion member is angled in a direction substantiallyperpendicular to the longitudinal axis of said insertion member, thedistal portion of said insertion member will be distanced from a tangentto the longitudinal axis of said insertion member.
 41. An endoscopecomprising: a first bending portion that is the distal portion of anelongated insertion member and has a plurality of joint piecesconcatenated so that the joint pieces can rotate freely; a secondbending portion located at the proximal end of said first bendingportion and has a plurality of joint pieces concatenated so that thejoint pieces can rotate freely; a first control portion included in ahand-held unit proximal to said insertion member, and used to bend saidfirst bending portion; a second control portion included in thehand-held unit proximal to said insertion member, and used to bend saidsecond bending portion; and an elastic member with which the peripheriesof said first bending portion and said second bending portion aresheathed; wherein the thickness of said joint pieces constituting saidsecond bending portion is different from the thickness of said jointpieces constituting said first bending portion, said joint piecesconstituting said second bending portion being thicker than said jointpieces constituting said first bending portion, and the second bendingportion accommodates a larger number of built-in components than thefirst bending portion.
 42. The endoscope according to claim 41, whereinsaid first control portion and said second control portion are providedcoaxially.
 43. The endoscope according to claim 36, wherein said firstcontrol portion is composed of a knob and said second control portion iscomposed of a lever.
 44. The endoscope according to claim 43, whereinsaid second control portion is located between said first controlportion and said hand-held unit.
 45. The endoscope of claim 41, whereina bending angle said first bending portion assumes when bent is set anda bending angle said second bending portion assumes when bent is set aredetermined so that when said second bending portion is bent by an angleθ and said first bending portion is bent θ+90° or more in a directionopposite to the direction in which said second bending portion is bent,and when the distal portion of said insertion member is angled in adirection substantially perpendicular to the longitudinal axis of saidinsertion member, the distal portion of said insertion member will bedistanced from a tangent to the longitudinal axis of said insertionmember.
 46. An endoscope comprising: a first bending portion that is thedistal portion of an elongated insertion member; a second bendingportion located at the proximal end of said first bending portion; afirst control portion included in a hand-held unit proximal to saidinsertion member, and used to bend said first bending portion; and asecond control portion included in said hand-held unit proximal to saidinsertion member, and used to bend said second bending portion, whereinrelative positions of axes of rotation of said first control portion andsaid second control portion to said hand-held unit do not vary when saidfirst control portion and said second control portion are operated andwherein said first control portion is located nearer the part which isheld with the operator's hand than said second control portion.
 47. Theendoscope of claim 46, wherein a bending angle said first bendingportion assumes when bent is set and a bending angle said second bendingportion assumes when bent is set are determined so that when said secondbending portion is bent by an angle θ and said first bending portion isbent θ+90° or more in a direction opposite to the direction in whichsaid second bending portion is bent, and when the distal portion of saidinsertion member is angled in a direction substantially perpendicular tothe longitudinal axis of said insertion member, the distal portion ofsaid insertion member will be distanced from a tangent to thelongitudinal axis of said insertion member.